Solar Driven Refrigeration Cycle Essay

2.3 SOLAR DRIVEN REFRIGERATION SYSTEMS IN BRIEF: Thermal driven cycles deal with are adsorption, desiccant, chemical reaction, absorption, ranking and ejector refrigeration cycles. The cycles driven by PV are thermoelectric, Stirling and vapor compression refrigeration cycles.

First introduced type of solar driven refrigeration system was solar driven absorption refrigeration system. Now, it is available in market as small packaged unit. An adsorption solar driven system consists of two phases or stages in cycle; adsorption and regeneration/desorption. A vapor compression refrigeration and Rankin power cycle can be combined as Duplex-Rankine system.AS highly pressured fluid is used to run the turbine

It works without pump and was developed by CARRE.It is also named as no-moving part and no-auxiliary energy supply system. To maintain a constant pressure in the whole system, an inert gas is used. The partial pressure of refrigerant is lowered in the evaporator to achieve the refrigeration effect. Diffusion absorption system has the same principal as the single effect system. However, it differs from single effect system in a way, that the total pressure in the whole system remains unchanged. In generator ammonia vapors are condensed before moving to the evaporator. Liquid ammonia in evaporator is exposed to the atmosphere and cooling is achieved, as ammonia gets evaporated due to low pressure. Next, a mixture of hydrogen and ammonia moves to the absorber, where water solution absorbs the ammonia.

Hydrogen go back to the heat exchanger and by a thermo siphon pump aqua ammonia solution is fed to the generator. The weak aqua ammonia solution goes to absorber by gravity. There is a variation in generators temperature between 120-180, as it depends upon the operating temperatures. At low cooling capacities the variation in COP is between 0.2 to

In this case water with lithium chloride acts as a refrigerant. CA is three phase absorption heat pump/chiller with the capacity to reserve energy in crystallized salt form.

In this process, standard absorption chillers are used which use lithium bromide/water and the processes carried out at vacuum conditions. The difference between traditional absorption chiller and TCA is that, TCA has the capacity to store energy in crystallized salt form to manage the variations in solar energy availability. It works intermittently with a charge and discharge phase in sequence with stand bye in between.

Fig _____ depicts a schematic and flow diagram of TCA system. To increase the wetted area and for better heat transfer lithium chloride/water solution is spread or sprinkled on heat exchangers. Desorption causes the formation of solid crystals, these crystals then fall into the vessel under the action of gravity. A sieve is used to prevent the crystals flow along with solution. In the bottom of vessel a slurry is formed from crystals.

TCA has the following